System of automatic block-signaling for electric railways.



FLTOWNSEND, DEGD.- I J. J. TOWNSEND, ADMINISTRATOR.

SYSTEM OF AUTOMATIC BLOCK SIGNALING FOR BLEGTRIG RAILWAYS.

APPLICATION FILED MAY 31, 1906.

Patented Ot.13,1914.

2 SHEET$-SHEBT l.

I J. J. TOWNSEND, ADlQiNI'STBATOB. I

SYSTEM OF AUTOMATIC M0011 SIGNALING FOR ELEGTRIG RAILWAYS.

' APPLIOATIOR FILED, MAY 31, 1906.

' 2 SHEETS-B1133"?- WITNESSES: INVENTO'R A ORNEY x er i r" "in i are inlinen rournsnnn, or new resign. r2; JOHN J. rowusnnn, nmnmrsrnnron cssew menses. rcwnsnnn, @ECMLEED, essisuon we answer. neinw es srsnsnscreensr, .e. comment-econ ee NEW some.

sieeificenen of Letters slatcnt,

were son ELEGTEIC summers.

I Pstensecl @cl 313,1314;

fzpplicscion filed may 31, 15506, Serial filo. $19A-23.

To all whom it may concern:

Be ii; known that I, FITZHUGH Towrzsnnn, a citizen of lghe UnitedStates, residing at- New York city, county and State of New York, hareinvented a System of Automatic Block-Signalin for Electric- Rnih Ways,of which the following is n specifiers tion.

l have invented an improved system of em.- lLOHlatlG block signaling,applicable to electrio rsilwn s in Which'nn alternaeing current isemployed to operate the cars. In my invention the control 0 5 thesignaling mechanisms is uccrmiplislied by segregated portioiiof thepropulsion current, acting either in conjunction with the propulsioncurrenfzQor with another rated portion thereof. I am able, therefore, touse a single feeder from the generazor, and both of the rails as returnsfor all current to the generator, thus ino'l'ermlly reducing the cost ofthe signaling system einployed. l urtherniore, by theerrengenient to hedescribed, a break in one rail will re: duce the action of the signalingcontrolling mechanisms to zero, even where several tracks are tiedtogether electrically. The operation of my system is independent ofslight changes in the relative conductivity of the trnilic rails; andleakage currents, whether direct or idle/routing, Willnot u ll'ecs thesignal mechanisms.

In the practice of 111; invention, she. truflic rails are divided intoblock sections, and the propulsion current flows from. bloc section toblock section along both rails Without being materially impeded; thepropulsion current flowing in the same direction in both rails, andreturning thus to the power generator. in each block; section asegregated portion of the propulsion current, or n current derived fromthe some source as the propulsion current, or from a separate generatorin synchronisni with the propulsion generator, is displaced in phasefrom the propulsion current- ,in the trnliic rails and l-runsn'iil'tedin each hlocl: section do n one rail and up the other, and limited inits llow to the block section. There is, therefore. a dii'lerem'eofpull! and plnisehetuecn the current employed to operate the cars andthat ciuployml to conlrol the signals, which difference is utilized incarrying out my invention.

means of s The accompanying diagrams will serve to illustrate myinvention.

Figure l illustrates'n single-phase, clitornatiiig currcnt'rnilmiy inwhich automatic block sigiialsare co troll'e from-she r ck circuits inaccordance with my invention; Fig. is a dis 7 ofcoils suitable for therelay bond oh Fig. 1; Fig, 3 illustrates a modification of my inventionin which the: tne lic rgrils Meltonl section by "a nected stench end ofone clock reuclnnce bond, fihe ends of, ndjacfens sections heirconucctedny n csenductor which includes a reactance, Figf'l illuslratesan arrangement similar so that shou hin 3, and boring :1,- inodifieclform or renctoncc bond at ench end of? the block seciions constructed inthe manner hereinafter (lescrihecl.

- In Fig. 1, l is the propulsion current generator supplying a, singlephase alternni'ing cnrrens e the outgoing; trolley Wire or feederconductor 2. Said propulsion current operates any motor vehicle 'as 5,which may he on the system. and returns to the power generator throughtraffic rails el. and 5, being conducted iron one block section to thenext by means of the coils of the relay bonds 6 and the resctance bonds7. X, if, E, are block sections. The relay looncl comprises two statoror field coils 8 and 9; the coil 9 should orererahlv have half the e g LD n znumber 01 turns 0:. Lllfi coil c. @118 end or the c 9 is connectedto the middle point of izhe coil 8, and the other end is connected tothe middle point of reactsnce bond 7, through conductor 10. 11 istlie'rnovshle member of the relay device and consists of s rotor Woundwith a short circnited winding eisher definite squirrel cage, in theordinary manner of induction motors and designed to give maximum "eorqueat stand still. a transformer, the 'niinary 13 of which is energizedfrom the outgoing feeder 2, through conductor 14. The secondary 153 isconnected across the trnilic rails d and 5 through conductor 16: andmeans of phase control 17 and 18. These are shown consisting of anadjustable resistance 7 and an adjustable reactance 1%, but of courseany other convenient 111621118 or phase control may be employed. Thphase controlling means is employed to nmlze the oi": the signalingcurrent suppliedhy lhe secondary e'rn n showing n arrangement 15 to thetrafiic rails 4c and 5 difier (about ninety degrees) from that of thepropulsion current. The phase adjustment may be fun ther. assisted, bygiving a suitable value to the power factor of the reactance bond 7;

said reactance bond may, of course, be made either of the closed or openmagnetic cuit type and may if desired, be designed to attain saturationat any suitable value of unbalanced propulsion current M. M. F. 19 is atransformer, the primary winding 20 of which is in parallel with that oftrans former 12. The secondary Winding 21 of transforn'icr 19 isconnected in series with the contact 22 and the solenoid coil 23 of thesignal 24. Said secondary .21 also supplies a current of particularphase to conductor Sui-d current flows through coil-9, and completes itscircuit through the means of phase control 26 which is here shownas anohmic resistance. The object of this means of phase control is to causethe current l lo-5ving through it to be substantially the same in phaseas the propulsion current. The lat; tcr phase is fixed by the powerfactor of the railway system, and it will be obvious that the means ofphase control 26 should preferably be adjusted to have the right combination of resistance and reactance so as to coincide in phase with that ofthe propulsion current in the trallic rails. In the event of there beingno propulsion current, thercfore, the auxiliary current thus supplied bytransformer 19 through conductor 25, will take the place of thepropulsion current and act in conjunction with the signaling current, incoil-8 of the relay, to hold the relay contact 92 closed by the exertionof a turning moment of the movable member 11.

In the operation of this form of my device, the prdpulsion current flowsfrom one block section to the next into both ends of the coil 8 of therelay bond 6 and out at the middle point of said coi through coil 9, andthence to-the adjacent reactancc bond 7, thus passing from one blocksection to the next. The action of the propulsion current in the relaybond is to produce a flux in the coil 9, and if the propulsion currentcarried by both trailic rails is the same in quantity, no flux would beproduced by said propulsion current in the coil 8. Should, however,there be unbalancing between the currents carried by the two trallicrails, some flux may be produced. in the coil 8. 3 Such flux,

however, will be in phase with the flux be fore mentioned produced inthecoil 9. It is plain, therefore, that acting by itself the propulsioncurrent can never produce a rotary field, since in order to produce thisresult, it would be necessary to have these fluxes displaced in phase incoils 8 and 9.-

Transfornicr 1.2 at the energy end of the block sect on sends a currentthrough the rails i and 5, which is displaced in phase by means of thedevices 17, 18, so as to differ (approximately ninet-y'degrees) in phasefrom the propulsion current, the phase of the latter being, of course,substantially constant on account of the fact that it is determined bythe power-factor of the system. This current, which I will call thesignaling current, passes down rail 4 through coil 8 and up rail 5, andit does not How through coil 9. This signaling current produces a fluxin coil 8, differing in phase from the flux in coil 9, due to thepropulsion current in the latter coil; consequently, the presence of thesignaling current in coil 8 acting in conjunction with the propulsioncurrent in coil. 9, will result in a rotary field, which normally, inthe absence of a car on the member 11 to close the contact 22, therebyallowing the solenoid 23 to be energized so as to hold the signal 24 ina clear position, as shown in block section Y. Then a car enters a blocksection, the wheels and axles short-circuit the traiiic rails 4 and 5,thus shunting the signaling current away from the coil *8. This removesthe flux of displaced phase from the coil 8 and destroys the rotaryfield. The result is that the turning moment of the movable member 11 isreduced to zero and the contact 22 is opened, thus denergizing the coil23 and sending the signal 24 to the danger position, as in block sectionZ. It is assumed that the direction of motion of the car is away fromthe generator. It may, therefore, be that under certain conditions,there rails ahead of the car 3, consequently, a signal might standwrongly at Danger 1n the current in the coil 9 of a relay bond. In orderto provide against this contingency, transformer 19 normally sends. acurrent similar to the propulsion current through the coil 9. It will beplain from this description, that any current whatever, of any blocksection to the next, and consequently traverses both the coils 8 and 9of a relay bond, cannot alone produce a rotary field, since the fluxesin both coils due to such currentmust be in phase owing to the seriesconnection.

. Fig. 1, shows a single track. in the event of there being more thanone track, the corresponding conductors 10 of the various tracks at eachblock section would be counected together by cross bonds so as tofacilitate the return of the propulsion current. If return feeders areemployed, they should .be connected to the return system at conductors10. This will be evident to vmy signaling engineer. It will be seen thatany ljfront of the car, due toa lack of propulsion.

frequency or phase which flows from one brealwin eitncr rail 4 or rail5, will reducethe turning momentof tlie movable member;

block section, causes the rotor or movablewill be no propulsion currentin the traffic I in case of a broken rail. would flow through half 0%winding 8, through Winding 9 and from conductor 10 through the crossbonding to the initial end of the block section, completing its circuitthrough {one-half of the reactance bond 7 at the initial end of theclock. It will be seen that under such circumstances. the fluxes in thecoils 8 and 9' would be of the same phase on account or the seriesconnection, so that there would be no rotary field and no turning momentof the movable member 11.

In Fig. 2, the coils 8 and 9.,are shown disposed in slots along. theperiphery of a stator core 27, in the ordinary manner of an inductionmotor and are displaced by ninety degrees. Conductors 28 and 29 aredesigned to be connected across the two trafiic rails of a blocksection, as is shown in the case of the terminal leads of coil 8 inFig. 1. Conductor 30 is to be connected to the middle point of thereactance bond 7, Fig. 1, of an adjacent block section. One terminal 31of coil 9 is connected to the middle point of coil 8, the coil 9 isshown as having half the number of turns of coil 8. The movable member11 shown placed concentrically Within the surrounding stator 27. It willbe understood or course that in actual practice, it will be preferableto dispose the end connections of the coils 8 and 9, around thecircumference of the stator core 27, as is usual in the construction ofinduction motors. Fig. 2, is entirely diagrarnmatiqand the contact arm,shaft bearing and. supporting base, which would be used on an actualrelay, are omitted.

In Fig. 3, a reactance bond 7, tapped at its middle point, is shownconnected across the rails at each end of a block section. The middlepoints of adjacent reactance bonds are connected together through anadditional reactancc bond 31, and which provides for transmitting thepropulsion current from one block section to the next. It will beunderstood that the reluctance of the magnetic circuit of the reactanccbonds 7 and 31 may, of course, be designed to suit conditions so tl atsaturation will occur with any desired value of the propulsion currenttraversing them. The power factor of said rencliancc bonds shouldpreferably be the same. The relay device -(3' comprises the stator coilsS' and 9, together with a movable member 11. The coil 8 is connected tothe terminals of the reactance bond 7 and the coil. 9' isconnectedacross the terminals of the reactauce bond 31. as in Fig. 1, that thepropulsion. current can It will be seen,

never produce a rotary held, since the currents in coils 8 and 9 mustnecessarily be in phase with each other and the flux produced by them,must consequently be in phase. in this arrangement of my device (Fig. 3)signaling current as in Fig. 1, is

transmitted "from a transformer 12 to the rails 4 and 5. This signalingcurrent, displaced in phase by the eviccs l? and 18, flows partlythrough the reactance bond 7 at the relay end, and partly through thecoil 8"; this current will produce a magnetic flux in the coil 8dififering in phase from. that in coil 9. The result will be a turningmovement of the movable memher 11, in the absence of a. car in the blocksection, the contact 22 being closed and the signal 94 held in the clearposition by means of the current supplied from the battery lVhen a carenters a block section, the signaling current will be shunted away fromthe coil 8', destroyin the rotary field of the relay (3, so thatthecontact 22 will 0 ion and the signal go to Danger, as shown in blocksection Z. It is assumed that the direction of traffic in this figure(3) is toward the generator. Thepropulsion current, therefore, afterleaving the Wheels of the car 3 must necessaril flow alon the tral'licrails 4 and ahead of the car and in the direction of its motion. it maybe presumed. therefore. that there will. be enough propulsion current inthe block sections ahead of the car lo act in conjunction with thesignalingcurrent of transformer 12, to hold the sigi'ials of theunoccaipied block ahead in the ole r position. On this account,therefore, transformer 19, which supplies the auxiliary current, asdescribed in Fig. l, is omitted as unnecessary. lit may, of course, besupplied, if desired. in a rail- Way system employing a number of cars,there will be a return power current flowing through the rails at alltimes.

In 4:, the trai'iic rails are connected at each end of each blocksection by one coil 33 of a reactancc bond 3%. llound in inductirerelation with, the coil 33 is a coil 35. The coil is connected betweenthe rail 5 and one terminal of the bond 31, which joins one blocksection to thenext. It will be seen, therefore, that the coil carriesthe entire propulsion current, while the coil 33 only carricshhen'opulsion current of rail 4. Coil 35 is Wound Willi half the number ofturns of coil 33 and in an opposite direction, 0 that the magneto motiveforces of IN; 'tu'o COllcZ'Wlll be equal and opposite, provided thepropulsion current equally dividcd between the rails land 5. The powerfactor of the bonds 3i and for the power current should be approximatelythe same.

:Ellk, operation of this l'orm of my invent on, is similar to thatdescribed in con ncctlon withv F l and Any current flowing from blocksection tolhlock sectioncannot by itself produce a rotary field andactuate the relay 6', but a signaling current of displaced phasesupplied by transformer 12 and flowing in coil 8, will, in conjunctionwith the current carried by coil 9', produce a turning Inomentof themovehle member 11, normally sending the signal 24: to the clearposition, as in block section Y. Similarly, as, in block section Z, thepresence of a car will shunt away the signaling current from the coil 8,destroy the rotary held and sending the signal 2e to the dangerposition.

In describing my invention, I have shown several arrangements ofcircuits, bonds, etc. It will be obvious to electricians that instead ofusing a single generator for the propulsion and signaling currents, Imay use two generators transmitting currents corresponding in frequency.Further, that instead of using a two-phase relay bond, 1 may use athree-phase bond. Further, I may change the general} arrangement of thecircuits without in any wise departing from the general rinciple of myinvention. What I wish to ave understood is. that I consider myself t hefirst to have described a system wherein the propulsion current 00* acts,with ano her current to produce a movement of the relays to indicate aclear signal and to indicate the continuity of the rails of the system;and further, the

employment in a signaling system of a sig-' nal controllin device havingits stator member energize when no car ison a block by the conjointaction of the propulsion and signaling currents. Further, the employ.-ment in such a system of reactance bonds having coils thereon soarranged that such bonds will inter-pose reactance to the alternatingsignaling current, but no reactance to the alternating power current;and further, the employment of means for insuring the operation of thesignal controlling device in the absence of the propulsion current, etc.

' Having thus described my invention, I claimr 1. A signaling system forelectric railways, comprising a trackway divided into block sections,react-ance bonds, one positioned at each end of each section, each bondcomprising a core and two coils thereon, one of said coils connectedacross the trackway and the other of said coils connected to one rail atone end and at its opposite end to the corresponding end of a similarcoil of the adjacent bond.

2. A signaling system for electric railways, comprising a source ofenergy, a trackway divided into block sections, reactance bonds betweenthe block sections, means for exciting a difi'erence of potentialbetween the rails of the block sections, a signal controlling device ineach block section normally energized by the current returning along therails and the current due to the difference of potential between therails, means for changing the phase relation of said currents, a localcircuit anda,-

signal under the control of each signal controlling device.

3. A signaling system for electric railways comprising a source ofenergy, a track way divided into block sections, reactance bonds, oneconnected across the rails at each end of each block section; aconnection be tween adjacent reactance bonds includin a reactance coil;means for exciting a di erence of potential betw en the rails of theblock sections, a signal controlling device in each block sectionincluding two coils, one of said coils connected across the rails, theother connected inshunt to said reactance coil, a local circuit and asignal under the control ofveach signal controlling device.

In testimony whereof, I afiix my signature, in the presence of twowitnesses.

FrrzHUon'TowusENnf VVi't-nesses FRANK Gonnon, Fnnnnmcn A. BLonNr.

